Reputation mostly. From what I've gathered, the components on most of them are pretty generic. BRS does color code their hoses, which is nice. They have good customer service and a lot of videos online to help you figure things out. One thing I'd go for is a refillable DI
canister. This will cost a little more up front, but save you in the long run. Speaking of which - make sure you get one with a DI
stage and not just RO
. Make sure you get what you need to hook it up like you want from the start as well.